You probably know her as Kelsey from Younger or Lizzie from Lizzie McGuire or, if we're going way back to where it all began, Wendy from Casper Meets Wendy. But when she's not on set, you can find Hilary Duff momming with her 6-year-old, Luca, and involving herself in philanthropy projects.

Clearly Duff is busy, but still, she values her 'me time'—even if that's just reading one chapter of a book while Luca plays Legos in the next room. Because she said what we can all nod in unison about: "Moms can't really take time off." And over the past few years, she's learned to stop trying to be the perfect mom—instead, realizing that spending quality time with Luca, teaching him about philanthropy, and scheduling time to care for herself, make her exactly the type of mom he needs.

We sat down with Hilary on behalf of Claritin and Boys & Girls Clubs of America as they launched the 20 Minutes of Spring Project—a campaign to get people outdoors and enjoy the season:

Parents.com: Between filming Younger, doing philanthropy work, and being a mom to a young boy, do you even believe in 'me time?'

Hilary Duff: Yes! But it's almost something you have to schedule in. Sometimes my 'me time' is sitting on the couch and watching a show after I put Luca to bed. Or it might be telling him, "Hey, I've been running around with you all day—I need to decompress and get off my feet." This was something I had to learn to do, and it took until this year not to feel guilty about doing it.

Being a mom is a full-time job, and as a working mom, I tried to compensate for a long time. But I came to realize I have to miss out on certain things. My sister and I will sometimes treat ourselves to a mani-pedi together, and I don't feel guilty about not checking my phone during that time. 'Me time' never looks like a full day—that's not realistic—but it's the little things like this that add up.

Parents: The school year is almost over—what are you looking forward to most about summer break?

Hilary Duff: Every year we spend some time on a lake in Canada. Luca waterskied for the first time last year! He was on kiddie skies and I was like, "How are those little legs keeping him up in the waves?!" He didn't even fall down. But, also, how did he get those toothpick legs?! He's my kid!

Parents: What are you and your son Luca's go-to outdoor activities?

Hilary Duff: He has a ton of energy, so his favorite game to play right now is tag, which is an exhausting game for adults. He can go forever! I have to barter deals by saying, "Four more rounds." And he'll go, "Five!" And I'm like, "No... Four…" He's so fast—I have to run at my full speed to catch him!

P: Why did you want to become involved with the "20 Minutes of Spring Project"?

HD: When I heard the statistics that more than 50 percent of people have allergies, I was like, "Well, yeah, I'm not surprised. I'm one of them!" So many people stay indoors because of it, but studies show that even just 20 minutes outside can make you happier. I notice the difference in my own son. I love that the campaign was built around getting out and doing an activity you love with your friends or family. There's also an amazing tie-in: If you post a picture of an activity you like to do in the spring and use #Claritin and #20MinutesOfSpring, 5 dollars will be donated to the Boys & Girls Club of America.

P: How are you teaching your son about philanthropy and giving back?

HD: We talk about donation at home by regularly cleaning out his toys and clothes. It can be harder for a kid this age to process but starting young helps. Every Friday his school has 'canned food day' and in October they do 'Sock-tober' where kids bring in socks for those in need. It's always amazing to hear Luca mention what they did that day to give back.

P: How has your own childhood upbringing shaped how you're taking on parenthood?

HD: I have such an amazing mom. She was always so playful with us, and I think I definitely got that trait from her when it comes to my relationship with Luca. But being an actress has helped me be creative with playtime. I'm very good at making up different voices and storylines.

But I don't think my job made me a good mom. I think I would have been a good mom either way. I couldn't wait to be a mom and knew that was something that had to be a part of my life. It's also easy to be really present and there when you have a great kid.